a. Field of the Invention
This invention relates to dumbbells and barbells used for exercising with weights.
b. Description of Related Art
Weights have been used for exercising for many years. There are several different kinds of weights, such as free weights and weight machines. Dumbbells are a type of free weight which are designed to be used with only one hand. Frequently two dumbbells will be used together with one dumbbell being grasped in each hand of the person exercising. Another type of free weight includes barbells. The term barbell refers to a bar or rod which usually has weights attached on both ends. The user generally grabs the barbell with both hands and lifts and maneuvers the barbells.
Barbells usually are adjustable, wherein the user selects the amount of weight and then loads the weight on to the barbell. Frequently the weights are cylindrical with a hole in the middle, wherein the barbell is slid through the hole until the weight abuts against an inner collar near one side of the barbell. After the desired amount of weight is slid up against the inner collar, an outer collar is slid against the weights to abut the weights opposite the inner collar. Therefore, the weights on the barbell are held in place between the inner and outer collar. This is done on both sides of the barbell so the weight is evenly balanced. Many barbells have a length of 32 inches between the two inner collars. There are many varieties of collars and weights which can be used with barbells. One example includes threaded barbells, wherein the outer collar is corresponding threaded and twists onto the barbell until it is locked into position.
Some dumbbells have adjustable weights, whereas other dumbbells are designed for a fixed weight. With the adjustable weight dumbbells, the user selects the amount of weight and then secures this weight to the dumbbell, similar to the barbell. Dumbbells which have a fixed weight are generally provided in a set so that the user will select the amount of weight he wants to exercise with and picks dumbbells with that weight. The user then exercise with those dumbbells. When the user desires to use dumbbells of a different weight, he returns the ones he was using to a rack or storage place and selects different dumbbells with the weight he desires.
There are dumbbells which have connecting devices so that the dumbbell can be connected to the end of a barbell. In this case, the dumbbell is used as a weight on the barbell. The user will typically place his hands on the barbell with the entire dumbbell being positioned outside of the hands of the person exercising.